Montana
Montana issues its own construction general permit. We have read General Permit for Storm Water Discharges Associated with Construction Activity (MTR100000) and list below the requirements we could cite to it, with the scope limits stated plainly. Screen your own acreage further down.
Who may prepare the plan
A credentialed preparer is requiredMontana requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Qualifying routes
Confirmed by direct read of the full MTR100000 permit (effective 1/1/2023, expires 12/31/2027, current as of Aug 2026). Part 3.2 requires DEQ-approved course certification for both SWPPP Preparers and Administrators, valid no more than 3 years. No acreage threshold gates this requirement — it applies to every site covered under the General Permit. No PE stamp/seal requirement exists anywhere in the permit.
Coverage trigger
The project disturbs 3 acres, at or above the 1 acre threshold, so it needs permit coverage.
The trigger people miss is the second one. A half acre lot inside a 40 acre subdivision is covered, because the larger common plan of development or sale is what counts, not the lot.
Worked for a three acre site with the receiving water unconfirmed. Each line says why it attached to this site rather than in general. Check the notes above for the site sizes this permit does not cover.
The SWPPP Preparer must plan and develop the SWPPP prior to submission of the NOI-SWC Package, and a complete, signed SWPPP must be submitted as part of the NOI-SWC Package.
A SWPPP Preparer is a designated individual who is responsible for planning and development of the SWPPP prior to submission of the NOI-SWC Package.
A complete NOI-SWC application package must be submitted to DEQ prior to discharging storm water associated with construction activity; no fixed number of days before the start of construction is specified.
Why this applies here: This is the deadline for a new site. A transfer to a new operator or an emergency related project has a different deadline.
To obtain coverage under the General Permit, the owner/operator must submit a complete Notice of Intent application package to DEQ prior to discharge storm water associated with construction activity under this General Permit.
Termination of coverage is event-triggered rather than day-count-triggered: permittees may request termination after achieving final stabilization and completing removal of temporary BMPs/equipment, by submitting a complete NOT-SWC form. Coverage and annual fee liability remain in effect until DEQ processes the NOT-SWC.
Coverage under the General Permit remains in effect until DEQ reviews and processes the NOT-SWC. The permittee is responsible for payment of annual fees for each calendar year covered under the General Permit. Failure to submit a NOT-SWC will result in accrual of annual permit fees.
Weekly self-inspection schedule option; no separate rain-triggered inspection required.
Why this applies here: You have not confirmed whether the site discharges to an impaired or high quality water. If it does, the increased frequency applies instead and this answer changes.
Conduct a routine inspection at least once every 7 calendar days;
Biweekly routine inspection plus a post-storm event inspection within 24 hours of the end of a rainfall event of 0.25 inches or greater, or within 24 hours of a discharge-causing snowmelt event.
Why this applies here: You have not confirmed whether the site discharges to an impaired or high quality water. If it does, the increased frequency applies instead and this answer changes.
Conduct a routine inspection at least once every 14 calendar days; Conduct and a post-storm event inspection within 24-hours of the end of a rainfall event of 0.25 inches or greater and within 24-hours of runoff from snowmelt
SWPPP Administrator — a designated individual who must obtain and maintain valid DEQ-approved course certification (valid up to 3 years) to plan, implement, maintain, revise, and update the SWPPP and conduct/document inspections.
Why this applies here: This is why Basinwise cannot perform your inspections. The permit requires a trained person physically on the site.
Inspections must be performed by a SWPPP Administrator as defined in Part 3.2.
Stabilization of disturbed areas must occur immediately for any portion of the construction project that will remain inactive for 14 or more calendar days, using erosion control BMPs.
Why this applies here: This applies at both land disturbance amounts.
Stabilization of disturbed areas immediately for any portion of the construction project that will remain inactive for 14 or more calendar days with erosion control BMPs.
close of the next business day
Maintenance must be documented and performed by the close of the next business day.
If new or replacement BMPs are required, or additional BMPs are necessary, these must be implemented or installed no later than 7 calendar days from the time of discovery.
If new or replacement BMPs are required to be implemented or installed or if additional BMPs are necessary, these additional measures must be implemented or installed by no later than seven (7) calendar days from the time of discovery.
To minimize soil disturbance, permittees must provide a natural (such as vegetated) buffer within the construction project area and maintain natural buffers around state waters; no specific minimum buffer distance in feet is set.
Provide a natural (such as vegetated) buffer within the construction project area; Maintain natural buffers around “state waters” as defined in Part 5;
SWPPP, NOI-SWC form, DEQ confirmation letter, SWPPP site maps, BMP specifications, SWPPP Administrator/Preparer documentation, all inspection records, and all reports of noncompliance must be retained by the permittee for a period of three years from the date of termination.
Why this applies here: The clock runs from permit expiry or termination, not from when the record was written, so on a multi year project every record stays live for the whole project plus three years.
These records are to be maintained by the permittee for a period of three years from the date of termination.
Your acreage, your receiving water, your answer. Runs in your browser, nothing is transmitted.
This is EPA's list, from the 2022 Construction General Permit. It does NOT govern in Montana, where the state issues its own permit and sets its own contents. It is here as a shape to expect, not as the requirement you will be held to.
Read the permit itself at the source document.
Montana issues its own construction general permit, and we have read General Permit for Storm Water Discharges Associated with Construction Activity (MTR100000). The requirements listed on this page, such as inspection frequency, who may inspect, stabilisation, corrective action and record retention, are cited to that permit rather than to EPA's. Anything we have not transcribed is left out instead of assumed to match the federal rule, and the scope note on this page says which sites the permit does not cover. Confirm the current permit and any site-size variant with Montana Department of Environmental Quality (Montana DEQ).
Montana requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
The inspection frequency is set by the Montana construction general permit, which we have not read. Confirm it with Montana Department of Environmental Quality (Montana DEQ).
Screening is free. Pro generates the site specific plan document and retains the inspection and corrective action log.